Phonic diaphragm



une 14, 1927. 1,632,068

H. Ce HARRESGN PHONIQ DIAPHRAGM -Filed June 19, 192.3y

y my ,477%

Patented June 14, 1927.

UNITED STATES lParnu'r oFFic'r..

HENRY C. HARRISON. F PORT WASHINGTON, NEW YORK, ASSIG-NOR TO WESTERNELECTRIC COMPANY, INCORPORATED, 0F NEW YORK, N. Y., A. CORPORATION OFNEW YORK.

PHONIC DIAPHRAGM.

Application tiled June 19, 1923. Serial Nc. 646,307.

The invention relates to plionic diaphragms and has for an object toprovide a diaphragm of such configuration that it will besti'f in bothradial and axial directions.

l The invention is not realized by a diaphragm having concentriccircular corrugations for xthe reason that such a diaphragm, while stiffin radial directions, has not the required stiffness in an axialdirection, that is, a direction along a line passing through the centerof the diaphragm and at right angles thereto.

-The object of. the invention is accomplished by providing' a diaphragmhaving corrugations such that any straight line drawn across thediaphragm, or any circle vdrawn on the diaphragm about any center on thediaphragm will cross a corrugation.

For further details, reference may be made to the drawings in which Fig.1 is a cross-sectional view of such a diaphragm when employed as a loudspeaker. Fig. 2 is a front elevation of the diaphragm in' Fig. 1. Fig. 3is-.a front elevation partly insection of a composite diaphragm made upof two diaphragme such as shown in Figs. 1 and 2. Fig. l is a sectionalelevation of Fig. 3. Fig. 5 is a sectional elevation of a conicaldiaphragm having an unsupported periphery and corrugated as in Fig. 2.Fig. 6 is an enlarged view of the corrugations.

Referring` in detail to the drawings, the diaphragm 1 may be of thin,still' material such as paper' or metal, and has closely spaced zig-zagcorru ations of the form shown in detail in ig. 6. In case the peripheryof the diaphragm 1 is to be clamped, as shown in Figs. 1. and 2, theperi heral portion 2 of the diaphragm is pre erably not corrugated. Thediaphragm portion 2 then rovides a flexible section between the rigidiaphragm 1 and the sup-1 port 3. The diaphragm may be driven at itscenter by any suitable drive such as the described in detail in Egerton'Patent No.

1,365,898--January 18, 1921.

- Figs. 3 Aand 4 show a modification wherein two diaphragms 5 and 6having corrugations, as inFig. '6, are fastened 'to an intermediate disc7 which is carried by the support 3. In this case the corrugations indiaphragm 5 extend generally at right angles to the corrugations ofdiaphragm 6, as

' electromagnetic device 4 which is shown and' illustrated in Fig. 3. Ifthe diaphragms 5 and 6 are of metal such as aluminum then theintermediate disc 7 may be of the same or similar material, and thediaphragms 5 and 6 may be fastened, for instance, by spot welding to thedisc 7. If desired, however, the diaphragms 5 and 6 and the diaphragm 1as well, may be of any other suitable light, stiff material such aspaper. In this case the Vdisc 7 may be of paper or similar material andthe parts 5, 6 and 7 may be fastened together by means of glue or thelike.

The diaphragm 8 in Fig. 5 has corrugations as shown in Fig. 6 and may beof the materials described/above. This diaphragm is illustrated as a coesupportedat its apex by a driving rod 9 of the electromagnetic device 4.

All of the diaphragme above described are large direct acting diaphragmsof the order o a foot or more in diameter and they may act' to directlyset the air into vibration without the use of a restrictive device suchas a horn.

If the diaphragm is of metal the corrugations may be formed by stampingor the like. If it is of material such as paper they may be formedeither during the process of manufacturing the textile sheet orafterwards by dampening a flat sheet-and pressing it into a corrugateddie.

What is claimed is:

1. A composite phonic diaphragm comprising a plurality of corrugateddiaphragms, the corrugations of one of said diaphragms crossing thecorrugations of another of said diaphragme.

2. A large direct acting phonic diaphragm having a plurality of paralleldiscontinuous ridges so positioned that the crest of the ridges formonly zig-zag lines consisting of short straight line sections seriallyconnected and extending in one general direction.

3. A large direct acting phonic dia hragm n iade of sheet materialhaving forme therelin a plurality| of parallel broken series of `formedof thin sheet material and having itsv he imm of zig-zag :ranges9 eachrange conn sistingjv of short straight line ridges joineii.

end-to-end and at an angle to one aifio'siier:

each range being separated from the f cent range throughout its extem byslinilariy shaped v n En Witness whereof, il hereuno subscribe my namethis 15 day of June [L iF/ HENRY C. -RRESIJ

